DESCRIPTION (adapted from the application's abstract): The University of California, San Diego AIDS Clinical Trials Unit (UCSD ACTU) proposes to continue participation in the Adult AIDS Clinical Trials Group (AACTG). Members of the UCSD ACTU have contributed to the leadership and development of the AACTG scientific agenda. They have designed, implemented and analyzed AACTG trials in antiretroviral therapy, opportunistic infections and outcomes. Laboratory studies conducted by the investigators have increased the understanding of the pathogenesis of HIV disease and complications, particularly in the areas of drug resistance, mycobacteria and cytomegalovirus disease. This group has established a record of patient accrual and retention by creating a program that is recognized by the community as being devoted to improving the lives of HIV-infected individuals. The ACTU has and will continue to make efforts to recruit as study participants women, minorities, and intravenous drug users. UCSD has a good relationship with the community advisory board that ensures community representation and enhances the overall effectiveness of the unit. The scientific contributions of the unit will focus on three aims: First, it will address the development of novel approaches to antiretroviral therapy and the incorporation of nested studies into clinical trials. The nested studies may provide insight into viral dynamics, resistance and reservoirs of HIV infection. Second, complications of HIV infection, which will provide leadership, innovative ideas and laboratory expertise for studies designed to increase understanding of the pathogenesis, prevention and treatment of opportunistic infections and the neurologic complications of HIV disease. Finally, attention will be given to outcomes and adherence, which will contribute expertise to the AACTG effort to evaluate outcome measures across clinical trials and to develop and test interventions, which may improve patient adherence.